Post by Admin on Sept 4, 2013 21:57:52 GMT
Overweight and obesity are the abnormal or excessive accumulation of adipose tissue generally resulting from a chronic positive energy imbalance[1], [2]. Recently it has been shown that globally approximately 1.0 billion adults are overweight, and a further 475 million are obese [3]. In the United States, the prevalence of obesity among adults increased by 1.1% between 2007 and 2009. If this trend continues, by 2050 close to 100% of Americans will be overweight or obese [4]. Obesity and overweight are the fifth leading cause of global death [1] and the second most preventable cause of death in the United States [5]. Obesity is a complex multifactorial disease but the causes are not yet completely known[6]. Weight gain is usually the result of a complex interaction between an individual's biology and environmental factors which lead to energy surplus [7]. In westernized society, one of the main causes of a chronic energy surplus is a reduced physical activity level owing to a sedentary lifestyle. Another equally important cause of energy surplus is overeating [8], [9]. Overeating in some degree may occur in many individuals; however, a proportion may develop an obsessive/compulsive relationship to certain foods [10]. These individuals chronically consume more food than they need to maintain health and show compulsive intake behaviours associated with loss of control of eating [9], [11].
In general, regardless of the various genetic predispositions and environmental influences, overeating is the primary factor responsible for the increasing prevalence of human obesity [14], [24]. To the best of our knowledge this is the first study reporting the contribution of ‘food addiction’ to the prevalence of human obesity in the general population [21], [29], [30]. One important finding is an estimation of the prevalence of ‘food addiction’ in the general Newfoundland population was at 5.4% (6.7% in women and 3.0% in men). In a previous study assessing obese patients with binge eating disorder (BED), the prevalence of ‘food addiction’ was reported to be as high as 56.8% [29], suggesting an overlap between binge eating and ‘food addiction’. The prevalence of ‘food addiction’ in obese individuals seeking weight loss treatment was 25%, while in another study obese subjects not seeking weight loss, the prevalence of ‘food addiction’ was 15.2% [30], [31]. In a cohort of junior college students with a normal BMI range, 8.8% met the YFAS criteria of ‘food addiction’; however the correlation between ‘food addiction’ clinical symptom counts and BMI was negligible [21], [39]. Our results indicated that 80–88.6% of food addicted individuals were overweight/obese based on Bray or BMI criteria providing strong evidence that ‘food addiction’ has contributed to the rising prevalence of obesity in the general population. Of note, food addicted individuals were also observed in the underweight and normal weight cohort, however in a lower number. The current findings suggest that obesity featured with ‘food addiction’ may represent an important subgroup of the obese with a distinctive aetiology. The identification of this subgroup will open a novel avenue to assess the aetiology of obesity and thus aid in finding new effective methods to treat and prevent obesity.
The subjects in the present study were recruited from the general Newfoundland population. The prevalence of overweight/obesity in the current study is similar to data reported from Health Canada on the province of Newfoundland (62.1%) [40]. The prevalence of ‘food addiction’ revealed in our study on the Newfoundland population may, to some degree, represent the prevalence in other Canadian provinces. Moreover our findings also suggests a potential difference between men and women in regards to ‘food addiction’, as overweight/obese women classified using BMI had a significantly higher rate of ‘food addiction’ as compared to men. This is similar to the case with eating disorders in which women also are significantly more likely to suffer from an eating disorder than men [41], [42]. Nevertheless larger studies in other populations are warranted to confirm the findings from our investigation.
The third major finding from the current study is the significant correlation between ‘food addiction’ and the severity of obesity in the general Newfoundland population. This finding appears to be robust as we were able to demonstrate this significant correlation throughout a number of analyses controlling for many confounding factors. Firstly, the clinical symptom counts of ‘food addiction’ was significantly correlated not only with BMI, but also with virtually all obesity related measurements including body weight, waist and hip circumferences, body fat and trunk fat percentage determined by DXA, an accurate measurement of body composition. This close correlation was seen in the non-food addicted group as well. We suggest that these robust and multiple correlations demonstrated a true association of ‘food addiction’ with human obesity. Additionally it was shown that obesity related variables were significantly different between food addicted and non-food addicted subjects. Participants who met criteria for ‘food addiction’ on average weighed 11.7 (kg) (25.79 lbs) more, had 4.6 higher BMI and possessed a 8.2% and 8.5% greater total body fat and trunk fat, respectively, as compared to non-food addicted subjects. These data provide the first direct evidence that ‘food addiction’ is strongly associated with obesity in the general population. Importantly, the individuals who met the criteria for ‘food addiction’ only represent between one fifth to one sixth of the total proportion of obese individuals in Newfoundland (25–30%) [40]. This suggests that ‘food addiction’ is likely an important factor in the development of human obesity but not the sole contributor.
www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0074832